Research And Implementation Of Test System For Fatigue Properties Of Metal Matrix Composite

Metal matrix composite is a new type of composite material with high transverse and shear strength and good fatigue mechanical properties.This kind of material has wide application prospect in aerospace,mechanical manufacturing,automotive,medical equipment and other fields due to its special performance.At present,there are still many problems in the application of metal matrix composites.The complex manufacturing process and the high price make the material difficult to be used in large scale in the industry.In order to improve the manufacturing process of materials,reduce the cost of materials,and improve the performance of materials,researchers need to study the properties of metal matrix composites.Therefore,it is necessary to develop a suitable fatigue test system to help researchers test the fatigue properties of metal matrix composite.The main research content of this paper is to design and implement the fatigue test system for metal matrix composite.The main task of the project is to design the electrical and control parts for the fatigue test system.The overall plan is designed according to the process flow and control indicators.The specific design can be divided into two parts:hardware design and software design.The hardware part mainly includes the main circuit and the electric control circuit of the system.The software part mainly includes the master computer monitoring interface,the slave computer logic control and the motion control.Under the guidance of the overall scheme,design the electrical schematic of the main circuit and the electric control circuit of the system.According to the test process flow,the program control flow and the host computer monitoring software are designed.Aiming at the stress control requirements appearing in the thermomechanical fatigue test,a scheme of stress closed-loop control using the model predictive control algorithm is proposed.The demand analysis is carried out according to the characteristics of the stress loading of the testing machine.Determine the control strategy and conduct theoretical research on the algorithm.The mathematical model is established based on the control object and system structure,and the application of model predictive control in stress control is studied.The system control parameters are determined by computer simulation and experimental tests.The stress closed-loop control part uses MATLAB simulation to verify the control effect of the model predictive control algorithm on the fast response system.The simulation data shows that the adjustment time after the system is added to the prediction algorithm is reduced by 15%compared with the previous one,and the control error is reduced from 1%to 0.5%.Finally,using the one-step model predictive control scheme,the algorithm is implemented in software,and the control effect is verified on the testing machine.After the model predictive control optimization is improved,it is applied in the stress closed-loop control of the system.The practical application results show that the algorithm can well control the stress loading of the test system,and its control accuracy can also meet the design index requirements.The design finally completed the design of the fatigue testing system for metal matrix composite,and passed the acceptance of the use unit,and all process flow and technical indicators met the requirements.